Such heading devices are used for the purpose of shaping the ends of bar-shaped workpieces, i.e., pipe or bar ends, the pipe wall or the bar ends being thickened, up to this point, one or more other local thickened areas (flares) still also additionally being provided in the course of the elongate workpiece by upsetting.
A hydraulic cold heading device is described in CH-PS 477 929, the device known therefrom having a very large and complicated overall construction, however, in which the use of installing tools is necessary to perform a tool change and the tool change itself is relatively cumbersome.
A hydraulic heading device for pipes and bars is known from DE 2629796 C, in which, however, a heating unit is used for heating the workpiece to be formed and thus forming is performed with heating. The heating occurs via two single-turn induction coils, which allow a precisely defined heating zone having predefined temperature gradients to be achieved, the front end of the part to be upset being heated more strongly than the remaining heating zone. This known heading device is complex in construction, operation, and in the event of a tool change because of the installed heating unit.
A further known cold heading device can be inferred from FR 2 231 449 A. This hydraulic device operates using multiple forming areas, whereby a unit having a very large overall construction results. A tool change, when it is to be performed, is relatively complex.